Systems that analyze online content such as webpages, media, and documents may employ binary classification schemes. In order to perform content classification, systems may employ machine learning techniques. For example, a machine learning system may be trained on email messages to learn to distinguish between spam and non-spam messages. In response to this “learning,” the system may be used to classify new email messages by flagging those that may be considered spam. When classifying content, the learning techniques employed by systems often utilize a form of regression analysis to analyze training data. Typical regression analysis algorithms, however, may provide less than optimal results especially in instances where training data is sparse.